Give this a shot...see what you get. Also Im assuming the Host paths are displaying correctly to the screen when it runs? Is there a backslash at the end of the hosts in the file?

This
$HostPath = '\\' + $Host + 'C$\users'
may need to be
$HostPath = '\\' + $Host + '\C$\users'

 Code:
$aTargets = FileIO('c:\scripts\hosts.txt', 'R')
For Each $Host in $aTargets
   ; run code to query each $Host value
   If Ping($Host)
      $HostPath = '\\' + $Host + 'C$\users'
      'Processing ' $HostPath ? ; for debugging or status reporting

      ; run any necessary command using $HostPath to reference the target path
      $logFile = @ScriptDir+"\Profile Sizes.ini"

      $profiles = DirList($HostPath, 3)

      For Each $profile in $profiles
         If Right($profile, 1) = "\"
            $profilename = Split($profile, "\")
            $profilename = $profilename[UBound($profilename)-1]
            $nul = WriteProfileString($logfile, $Host+"\"+$profilename, "Desktop", fnGetFolderProp($profile+"Desktop","Size"))
            $nul = WriteProfileString($logfile, $Host+"\"+$profilename, "Documents", fnGetFolderProp($profile+"My Documents","Size"))
         Endif
      Next
   Endif
Next


Function fnGetFolderProp($sFldr,$sProp)
   Dim $objFSO, $objFldr, $nul
   $objFSO = CreateObject("Scripting.FileSystemObject")
   If Not VarType($objFSO)=9 Exit 1 EndIf
   $objFldr = $objFSO.GetFolder($sFldr)
   If Not VarType($objFldr)=9 Exit 3 EndIf
   $nul=Execute("$$fnGetFolderProp = $$objFldr."+$sProp)
   If VarType($fnGetFolderProp)=0 Exit 87 EndIf
EndFunction

Function dirlist($dirname, optional $options)
  dim $filename, $counter, $filepath, $mask
  dim $list, $sublist, $subcounter
  $counter=-1
  $dirname=trim($dirname)
  if $dirname=''
    $dirname=@CURDIR
  endif
  if right($dirname,1)='\'
    $dirname=left($dirname,len($dirname)-1)
  endif
  if getfileattr($dirname) & 16
    $mask='*.*'
  else
    $mask=substr($dirname,instrrev($dirname,'\')+1)
    $dirname=left($dirname,len($dirname)-len($mask)-1)
  endif
  redim $list[10]
  $filename=dir($dirname+'\'+$mask)
  while $filename<>'' and @ERROR=0
    if $filename<>'.' and $filename<>'..'
      select
      case (getfileattr($dirname+'\'+$filename) & 16)
        if $options & 1
          $counter=$counter+1
          if $options & 2
            $list[$counter]=$dirname+'\'+$filename+'\'
          else
            $list[$counter]=$filename+'\'
          endif
        endif
        if ($options & 4)
          $sublist=dirlist($dirname+'\'+$filename+'\'+$mask,$options)
          if ubound($sublist)+1
            redim preserve $list[ubound($list)+ubound($sublist)+1]
            for $subcounter=0 to ubound($sublist)
              $counter=$counter+1
              if $options & 2
                $list[$counter]=$dirname+'\'+$filename+'\'+$sublist[$subcounter]
              else
                $list[$counter]=$filename+'\'+$sublist[$subcounter]
              endif
            next
          endif
        endif
      case ($options & 2)
        $counter=$counter+1
        $list[$counter]=$dirname+'\'+$filename
      case 1
        $counter=$counter+1
        $list[$counter]=$filename
      endselect
      if $counter mod 10
        redim preserve $list[$counter+10]
      endif
    endif
    $filename = dir('')
  loop
  if $counter+1
    redim preserve $list[$counter]
  else
    $list=''
  endif
  if $mask<>'*.*' and ($options & 4)
    $filename=dir($dirname+'\*.*')
    while $filename<>'' and @ERROR=0
      if $filename<>'.' and $filename<>'..'
        if (getfileattr($dirname+'\'+$filename) & 16)
          $sublist=dirlist($dirname+'\'+$filename+'\'+$mask,4)
          if ubound($sublist)+1
            redim preserve $list[ubound($list)+ubound($sublist)+1]
            for $subcounter=0 to ubound($sublist)
              $counter=$counter+1
              if $options & 2
                $list[$counter]=$dirname+'\'+$filename+'\'+$sublist[$subcounter]
              else
                $list[$counter]=$filename+'\'+$sublist[$subcounter]
              endif
            next
          endif
        endif
      endif
      $filename = dir('')
    loop
  endif
  if $counter+1
    redim preserve $list[$counter]
  else
    $list=''
  endif
  $dirlist=$list
endfunction

Function Ping($Computer,$GetIP,optional $LoopCount,optional $TimeOut)
if $GetIP
dim $ip, $ipfile, $
$ipfile = @scriptdir + '\ip.txt'
shell '%Comspec% /q /e:1024 /c for /F "tokens=2 delims=[]" %%i IN ('+ chr(39)
+ '"ping ' + $Computer + ' -n 1 | find "]""' + chr(39) + ') do echo %%i >"' + $ipfile + '"'
$ = open(10,$ipfile,2) $ip = readline(10) $ = close(10) del $ipfile
if $ip
$Ping = $ip
else
$Ping = 'Bad IP address ' + $Computer + '!'
endif
exit 0
else
if $TimeOut
for $c = 0 to $LoopCount
shell '%Comspec% /C ping ' + $Computer + ' -n 1 -w ' + $TimeOut + ' | find /C "TTL=" > nul'
if @error = 0
$Ping = 1
exit 0
endif
next
else
for $c = 0 to $LoopCount
shell '%Comspec% /C ping ' + $Computer + ' | find /C "TTL=" > nul'
if @error = 0
$Ping = 1
exit 0
endif
next
endif
$Ping = 0
endif
EndFunction